Uptake and transfer factors of137Cs by mushrooms

Abstract

The 137Cs content of 118 species (668 samples) of higher fungi collected in the period from August 1984 to October 1989 at three different locations in Styria, Austria, was determined by gamma-spectrometry. The Cs-content of most mushrooms has been increasing since September 1986. In order to find out which factors determine the 137Cs-contamination of mushrooms and the transfer-value soil to mushroom, the concentration of total and plant-available radiocesium in soils as well as the pH-value, the content of humus, clay, silt, sand, exchangeable cations, the composition of the clay minerals, and the particle size distribution of the soils of two different locations were examined. The higher the 137Cs contamination of the soil, the thicker the layer of humus and the higher the content of humus, the lower the pH-value, and the lower the amount of essential cations, especially of K+, the higher the amount of 137Cs plant-available will be. Therefore, the contamination of the mushrooms in the coniferous forest of Koralpenblick (1000 m) is higher than in the mixed forest at the Rosenberg around Graz at approx. 500 m height. Of 26 different species of mushrooms measured at both sites, only 61% show the highest TF-values soil to mushrooms also at the Koralpenblick. In the spruce forest at Koralpenblick there are many species of mushrooms with high 137Cs-contamination which were not found at the Rosenberg. However, the properties of the species to which a mushroom belongs are more important than environmental conditions and soil properties. The transfer values of 40K stay within narrow bounds, whereas those of 137Cs differ widely.

Radiocesium storage in soil microbial biomass of undisturbed alpine meadow soils and its relation to 137Cs soil–plant transfer

“…is clearly dominated by fungi (O50% of total microbial biomass), whereas the fungal contribution to total microbial biomass is significantly lower in the low-altitude sites and deeper mineral soil layers (!15%). Fungi are able to accumulate considerable amounts of radiocesium in their mycelia and fruit bodies (Heinrich, 1992;Ro¨mmelt et al, 1990;Steiner et al, 2002). They are suggested to significantly contribute to the plant available pool of radiocesium in grassland soils (Dighton et al, 1991).…”

Mushrooms: Radioactive Contamination of Widespread Mushrooms in Japan

“…However, the radiocesium activity ratio in mushrooms relative to the soil in a fi eld study were rather low and the ratio was often <1 (Heinrich 1992 ). Different fungal species also exhibit widely varying degrees of 137 Cs contamination; however, saprotrophic mushrooms tend to have lower TF of 137 Cs than the symbiotic mycorrhizal fungi (Heinrich 1992 ;Sugiyama et al 1993 ). Cesium shows a similar behavior to potassium.…”

“…For example, the transfer factors (TF) for radiocesium in mushrooms were reported to be 2.6-21 in several culture tests (Muramatsu et al 1991 ;Ban-nai et al 1994 ). However, the radiocesium activity ratio in mushrooms relative to the soil in a fi eld study were rather low and the ratio was often <1 (Heinrich 1992 ). Different fungal species also exhibit widely varying degrees of 137 Cs contamination; however, saprotrophic mushrooms tend to have lower TF of 137 Cs than the symbiotic mycorrhizal fungi (Heinrich 1992 ;Sugiyama et al 1993 ).…”

Artificial environmental radionuclides in Europe and methods of lowering their foodstuff contamination – a review

“…Fungi, as one of the most important constituents of forest ecosystem are capable of accumulating a significant amount of radionuclides including 137 Cs (Heinrich 1991;Škrkal et al 2013;Guillen and Baeza 2014). It is due to their heterotrophic metabolism, significantly different from green plants, and dependence on the supply of final organic compounds (Yoshida and Muramatsu 1994).…”